Emkhakheni kagesi, enye yezinto ezibalulekile ezintanjeni zikagesi namakhebuli i-insulating and jacketing materials.Iminyaka eminingi, izinto zokufakelwa ezivelele zamakhebuli kagesi kwakuyiphepha elifakwe uwoyela ngenxa yezakhiwo zalo ezinhle zikagesi.Futhi inamandla okumelana nezinga eliphezulu lokugcwala okushisayo ngaphandle kokuwohloka ngokweqile.Kodwa-ke, ngenxa ye-hygroscopicnature yayo, isikhwama sensimbi sinomswakama.Ngakho-ke, bekunesidingo esizwakala isikhathi eside sezinto ezifakwa kukhebula ezisebenza ngogesi, ebezinenhlanganisela yemvelo engeyona i-hygroscopic ye-thermoplasticmaterials.
Ucwaningo oluqhubekayo lwento enjalo yamaphupho ekugcineni luholele ekutholweni kwe-polyethylene exhumene.I-crosslinking yama-polymers ibhekisela ekuguqulweni kwezakhiwo ze-polymer ngokufaka izixhumanisi zamakhemikhali phakathi kwama-macromolecules ngamanye.Ngokuxhumanisa ama-polymers afana ne-aspolyethylene, inethiwekhi yezibopho ezintathu-ntathu kwakheka phakathi kwamaketanga e-polymer okwandisa isisindo samangqamuzana.Lokhu kufana nendlela ye-'vulcanising rubber'.
Inqubo evamile 'ye-vulcanisation' ihlanganisa ukushisisa nokwengeza isibabule noma amanye amakhemikhali ukuze enze izixhumanisi phakathi kwezimpawu zamaketanga amade ama-molecule e-elastomer.Le nqubo yaqala kudala futhi isasetshenziswa.Impahla ye-polymer incike kwinani lesulfure elisetshenzisiwe.Ngaphezu kwalokho isibabule esisetshenzisiwe siwukuthi, kuba nzima nakakhulu umkhiqizo, okwazi ukumelana nezinga lokushisa eliphakeme, izingcindezi kanye nezinselelo zemishini ekuthembekeni kwawo.Kodwa ukushiswa kwesulfure kunezihibe ezinkulu maqondana nempilo yabantu kanye nemvelo futhi kunezinkinga ezithile zomnotho.Ngaphezu kwalokho, idinga izinga lokushisa eliphezulu ukuze iqale ukusebenza kwamakhemikhali futhi ikhiphe amagesi anephunga elibi futhi anobuthi kanye nokukhiqiza izinsalela zamakhemikhali eziningi ezingadingeki okufanele zikhishwe emkhiqizweni wokugcina.
'I-radiation crosslinking' iyindlela efakazelwe kahle edlula yonke le mithelela emibi yenqubo ye-thevulcanization.Kuyindlela yokushisa yegumbi enenzuzo yezindleko ngokwayo.Ilawulwa kalula futhi izakhiwo ezifiselekayo ze-polymer zitholakala ngokushintsha umthamo (isikhathi sokukhanya).Izinto eziguquliwe azikho ngaphansi kwalezo ezikhiqizwa i-sulphurvulcanization.
Into eyinhloko ye-crosslinking ukuthuthukisa ukumelana nokushisa.Ngokuvamile, izinga lokushisa eliphezulu elivumelekile kwisekethe elifushane lingu-140⬚C kukhebula le-polyethylene elingaxhunywanga lingathuthukiswa libe ngu-250⬚C ngenqubo yokuxhumanisa ngemisebe.Umgomo wesibili ovame kakhulu umphumela wenkumbulo oboniswa yi-shrink tubing.Lena impahla engavamile neyigugu ye-polyethylene ene-irradiated futhi igcinwa unomphela ngaphakathi kwe-polymer kungakhathaliseki isikhathi kanye nanoma iyiphi inombolo elandelayo yokuguqulwa.Ngakho-ke, uma i-polyethylene ikhanyiswa ngengxenye ye-crystalline ifomu (okungukuthi ngaphansi kwendawo yokuncibilika kwayo) bese ishisisiwe ukuze ikhiphe amakristalu, ingakhubazeka kakhulu (isb. ngokunwebeka) bese ipholiswa futhi ibe yikristalu ukuze ishintshe esimweni sayo esisha.Uma okokusebenza kushisisa futhi kuncibilika ngaphezu kwalokho, lawa makristalu ayanyamalala futhi i-polyethylene efana nerabha izothambekela ekubuyeleni esimweni uma ibekwe ngesikhathi sokushiswa kwemisebe cishe ezinyangeni noma iminyaka ngaphambili.Ishubhu eshwabene ikhiqizwa ngokukhipha i-polymer eyakhiwe ngokukhethekile ibe yishubhu bese ixhumanisa leli shubhu.Ngemuva kokuxhumanisa, ithubhu iyashiswa, inwetshwe futhi ipholiswe ngendlela enwetshiwe.Leli shubhu elinwetshiwe, uma selishiselwe kabusha lizohlehla libuyele esimweni salo sangempela, okungenxa yomphumela wenkumbulo wokuphambana.Njengoba ama-polymermolecules exhunywe kwamanye amakhemikhali futhi engasakwazi ukuhamba ngokungahleliwe, izici ezihlukene njengokumelana nokushisa, ukumelana nemihuzuko, ukuzinza kwe-dimensional, impahla yokunamathela njll. ziyathuthukiswa.Ngakho-ke, i-crosslinking ingase inikeze izinto ezifiselekayo ku-polymer, okungukuthi ukuqina, ukuguquguquka, ukumelana nomthelela, ukumelana namakhemikhali njll. I-polyethylene ene-irradiated isetshenziswa kakhulu ekushiseni kwamafilimu ashwabenekayo ukupakisha, ukuhlanganisa kanye nokuxhuma ugesi, okungashisisa kalula ukuncibilika kwezinye izingxenye. .Ngokuvumelana nezimo, intambo exhumene/ukufakwa kwekhebula kulula futhi akunamkhawulo wobude.Ngaphezu kwalokho, awukho umgodla wensimbi odingekayo ukuze ulungiswe.Ngaphezu kwalokho, izakhiwo eziqinile ziphakathi phakathi kwe-thermoplastic ne-anelastomer.
Isikhathi sokuthumela: Feb-18-2017